Editing Engine

{{bothversions}}
[[File:engine design.png|thumb|Setting background tech parameters]]
The '''engine''' is ship propulsion [[component|system]] that allow interplanetary travel. Engines propel the ship by burning [[fuel]]. [[Space station]]s without engines or [[ship]]s with damaged engines will be unable to move unless [[tug|towed]].

==Overview==
An engine is an absolute necessity for any ship that wishes to travel faster than 1km/s. Any number of engines can be mounted on a ship, although only one variety of engine may be mounted per ship. 

There are [[military components|military]] and [[commercial components|commercial]] engines, the difference being that an engine of size 25 HS and larger with a power rating of -50% and lower is automatically classified as commercial. Military engines flag any ship they are on as [[military vessels]], and thus subject to maintenance failures and requiring overhaul. Commercial-engined ships tend to be slower than their military-engined counterparts. This is offset by a much better fuel efficiency and no [[Ship Maintenance|maintenance]] failures. In effect, commercial engines are trading a high maximum speed for fuel economy.

You might get to the point where your empire operates hundreds of freighters, asteroid miners, fuel harvesters, tugs, troop transports and other non-warships. They need engines with great fuel economy or they'll eat up your reserves faster than you can build new [[Fuel Refinery|fuel refineries]] or [[Sorium Harvester]]s. 

The total power output from a ship's engines will determine the speed of the ship. Speed is one of the most important aspects of a ship. Superior speed means higher capacity per time for cargo ships, and a battle fleet with higher speed has a significant advantage, able to dictate the range of the engagement, intercept the other force, or disengage from a hostile force.

All engines use fuel to operate, limiting cruising range, with high powered engines consuming exponentially more fuel than the default value.  Range and speed are generally increased at each other's expense, or by building a significantly larger and more resource-hungry ship. As you research Fuel Consumption [[technology]], you can design engines that will use less fuel for the same power output. Fuel efficiency can also be improved with larger individual engines ([[CSharp|C#]] only). 

Engines create a thermal signature, one that can be detected by [[Thermal Sensors]], so having high-powered or numerous engines on a spy ship is not advisable. By dropping a ship's speed or by designing engines with Thermal Reduction, a ship's thermal signature can be reduced.

[[Missiles]] also have engines, but with somewhat different rules from ship engines. These function along the same lines, though. In [[VB6]], they have a separate design menu, with slightly different mechanics. In [[CSharp|C#]], they are designed as part of the missile's design, using the same basic mechanics as ship engines. The main differences are that you can select much smaller and more granular sizes, and that your power level can go twice as high. For example, if you have researched Maximum Engine Power Modifier x1.75, your ship engines can have power levels as high as 175%, but your missile engines can go to 175% * 2 = 350% instead.  

==Examples==
Let's say you have researched Magneto-plasma Drive Tech and Fuel Consumption x 0.4. 

====Commercial engines====
The minimum size for commercial engines is 25 [[HS]] (= 1250 tons) and the power modifier needs to be -50% (or less). If you have, say, 60% fuel consumption rate researched, it looks like this:

<code>Commercial Magneto-plasma Drive  EP200.00<br>
Engine Power 200.00      Fuel Use Per Hour 13.42 Litres<br>
Fuel Consumption per Engine Power Hour 0.067 Litres <br>
Size 25 HS  (1,250 tons)      HTK 5<br>
Thermal Signature 200.0      Explosion Chance 5%      Max Explosion Size 50<br>
Cost 50.0000      Crew 12<br>
Commercial Engine<br>
Development Cost 500 RP<br>
Materials Required<br>
Gallicite  50.0000</code>

Compare this to an engine that's twice the size (50 HS = 2500 tons) and twice the power:

<code>Commercial Magneto-plasma Drive  EP400.00<br>
Engine Power 400.00      Fuel Use Per Hour 18.97 Litres<br>
Fuel Consumption per Engine Power Hour 0.047 Litres <br>
Size 50 HS  (2,500 tons)      HTK 7<br>
Thermal Signature 400.0      Explosion Chance 5%      Max Explosion Size 100<br>
Cost 100.0000      Crew 25<br>
Commercial Engine<br>
Development Cost 707 RP<br>
Materials Required<br>
Gallicite  100.0000</code>

Fuel use is only 19 litres per hour, compared to 27 if you had installed two 200EP engines instead, for the same power output. Development (i.e. research) cost to design this engine is higher, though. Size 50 is the maximum in VB6, but you can keep increasing the size further in C#, up to a maximum of 20,000 tons (400 HS), with suitable research into Maximum Engine Size techs. 

====Military engines====
Now you decide to design a compact but powerful standard engine for your medium-sized warships. You intend to stick two of these on a frigate, three on a destroyer and so on. 15 HS (= 750 tons) sounds like a good size and you select a power modifier of 175% because you need that extra bit of ''wroooom'':

<code>Magneto-plasma Drive  EP420.00<br>
Engine Power 420.00      Fuel Use Per Hour 833.59 Litres<br>
Fuel Consumption per Engine Power Hour 1.985 Litres<br> 
Size 15.00 HS  (750 tons)      HTK 3<br>
Thermal Signature 420.0      Explosion Chance 17%      Max Explosion Size 105<br>
Cost 210.00      Crew 26<br>
Military Engine<br>
Development Cost 1024 RP<br>
Materials Required<br>
Gallicite  210.00</code>

Research costs are significant, and fuel use is ''forty-four times'' higher than for the commercial engine of similar power. You can save a lot of weight with military engines, but all that engine power severely limits your range. Perhaps your destroyers would do better with a single, large engine instead? Let's see:

<code>Magneto-plasma Drive  EP1260.00<br>
Engine Power 1260.00      Fuel Use Per Hour 1443.81 Litres<br>
Fuel Consumption per Engine Power Hour 1.146 Litres <br>
Size 45 HS  (2,250 tons)      HTK 6<br>
Thermal Signature 1260.0      Explosion Chance 17%      Max Explosion Size 315<br>
Cost 630.00      Crew 79<br>
Military Engine<br>
Development Cost 1774 RP<br>
Materials Required<br>
Gallicite  630.00</code>

It has three times the power of the 420EP engine, but research costs, which scale with engine size, are now getting pretty high (especially since you'll need to research different models for other classes). Having only one engine means being more vulnerable to lucky enemy hits, too. Fuel use compared to three smaller engines is about 42% lower, though.

==Background Tech ([[CSharp|C#]])==
'''Engine Technology''' determines the power output per HS (thrust:weight ratio, essentially) of the engine. Conventional empires start with the Conventional Engine technology, in able to represent pre-[[TN]] engines pushing around hulls constructed from conventional materials. Conventional engines have a base output of 1 unit. One unit of engine power are the amount of power required to propel 50 tons (1 HS) against the Trans-Newtonian drag at 1000 km/s (this unit is also known as a EP (engine power)). Therefore, for a ship or missile

 Speed = (Total Engine Power / Total Class Size in HS) * 1000 km/s
 or
 Speed = (Total Engine Power / Total Class Size in tons) * 50,000 km/s

You are obviously going to be using the best tech, which is automatically selected.
{| class="wikitable" style="text-align: center;"
! Technology !! Conventional !! Nuclear Radioisotope !! Nuclear Thermal !! Nuclear Pulse !! Nuclear Gas-Core !! Ion !! Magneto-Plasma !! Magnetic Confinement Fusion !! Inertial Confinement Fusion !! Solid Core Anti-matter !! Gas Core Anti-matter !! Plasma Core Anti-matter !! Beam Core Anti-matter !! Photonic !! Quantum Singularity
|-
! Power per HS
|1||5||6.4||8||10||12.5||16||20||25||32||40||50||64||80||100
|-
! RP cost
| - ||1,000||2,000||4,000||6,000||10,000||20,000||40,000||80,000||150,000||300,000||600,000||1,250,000||2,500,000||5,000,000
|}

'''Size''' determines the largest engine that can be built. In C#, larger engines are more fuel-efficient, with standard efficiency for 500 ton (10 HS) engines, and smaller engines losing fuel efficiency as the square root of the size reduction. For example, an engine of 125 tons = 2.5 HS would be one-quarter the size of the 10 HS baseline, so its fuel efficiency would be sqrt(1/4) = 1/2 of the fuel efficiency of a 10 HS engine. This means it uses twice as much fuel per engine power per hour (commonly abbreviated as "per EPH"). Conversely, a 40 HS engine would be 4x baseline size, so its efficiency is a factor of sqrt(4) = 2 better, meaning it uses half as much fuel per EPH. 
{| class="wikitable" style="text-align: center;"
! Maximum Size !! 25 !! 40 !! 60 !! 100 !! 160 !! 250 !! 400
|-
! RP cost
| - ||2,000||4,000||8,000||15,000||30,000||60,000
|}

'''Power/Efficiency Modifiers''' allows for creating super-tuned or de-tuned engines, increasing output power at the cost of fuel efficiency or vice versa.  Making these alterations affects several other statistics as well as just the engine power. 
* The risk of explosion if an engine is hit is equal to its power ratio times 10%, so a miitary engine at 150% power has a 15% chance of causing a secondary explosion if the engine takes [[Internal_Damage|damage]]. 
* Fuel use is proportional to the power modifier to the power of 2.5, so (for example) doubling an engine's power ratio will increase its fuel use by a factor of 2^2.5 = 5.66 times the original fuel use. 
* An engine's [[Gallicite]] cost is equal to half its engine power if it has a power ratio of 100% or higher. Below 100%, you also multiply by the power ratio as well, so the 400 EP commercial engine described above would cost 400 * 0.5 [base multiplier] * 0.5 [power ratio] = 100 Gallicite. This means de-tuned engines are very cheap, but they leave your ships extremely slow, so going much below 30% is not popular with most players. 
{| class="wikitable" style="text-align: center;"
! Modifier !! 0.1 !! 0.15 !! 0.2 !! 0.25 !! 0.3 !! 0.4 !! 0.5 !! 1 !! 1.25 !! 1.5 !! 1.75 !! 2 !! 2.5 !! 3 
|-
! Fuel per EPH
|0.003||0.009||0.018||0.03||0.05||0.1|| 0.18 || 1 ||1.75||2.76||4.05||5.66||9.88||15.59
|-
! RP cost
|30,000||15,000||8,000||4,000||2,000||1,000|| - || - ||1,000||2,000||4,000||8,000||15,000||30,000
|}

'''Fuel Consumption''' determines the rate at which fuel is consumed. A ship running at its max speed consumes fuel (in litres) at a rate equal to its engine power every hour, before modifiers. A ship with one Conventional military engine (total power output: 1 EP) consumes 2.4 litres of fuel per day. If it had a fuel tank capable of carrying 50,000 litres (the standard fuel tank size), it could operate for 20833 days (about 58 years). If its max speed was 100 km/s, it could travel for 179 billion km before running out of fuel (about 15 round trips to Pluto).

{| class="wikitable" style="text-align: center;"
! Modifier !! 1 !! 0.9 !! 0.8 !! 0.7 !! 0.6 !! 0.5 !! 0.4 !! 0.3 !! 0.25 !! 0.2 !! 0.16 !! 0.125 !! 0.1
|-
! RP cost
| - ||1,000||2,000||4,000||8,000||15,000||30,000||60,000||120,000||250,000||500,000||1,000,000||2,000,000
|}

'''Thermal Reduction''' applies a reduction to the thermal signature generated by the engine. This makes it harder to be detected by Thermal sensors. Great for engines meant for stealth ships, at the cost of increased cost to research and build.
The thermal signature for an engine is equal to its power output * its thermal reduction modifier. A 25% reduction to a 40 EP engine would cause it to have a thermal signature of 30.
{| class="wikitable" style="text-align: center;"
! Signature (%) !! 100 !! 75 !! 50 !! 35 !! 25 !! 16 !! 12 !! 8 !! 6 !! 4 !! 3 !! 2 !! 1
|-
! Cost Increase
| - ||25%||50%||75%||100%||125%||150%||175%||200%||225%||250%||275%||300%
|-
! RP cost
| - ||1,500||3,000||6,000||12,000||25,000||50,000||100,000||200,000||400,000||750,000||1,500,000||2,500,000
|}

==Background Tech ([[VB6]])==
'''Engine Technology''': 
{| class="wikitable" style="text-align: center;"
! Technology !! Conventional !! Nuclear Thermal !! Nuclear Pulse !! Ion !! Magneto-Plasma !! Internal Confinement Fusion !! Magnetic Confinement Fusion !! Inertial Confinement Fusion !! Solid-core Anti-matter !! Gas-core Anti-matter !!Plasma-core Anti-matter !! Beam Core Anti-matter !! Photonic
|-
! Power per HS
|0.2||5||8||12||16||20||25||32||40||50||60||80||100
|-
! RP cost
| - ||2,500||5,000||10,000||20,000||40,000||80,000||150,000||300,000||600,000||1,250,000||2,500,000||5,000,000
|}
Note the very small name difference between In'''tern'''al Confinement and In'''erti'''al Confinement Fusion, as these are significantly different techs with very similar names. 

'''Power/Efficiency Modifiers''': 
{| class="wikitable" style="text-align: center;"
! Modifier !! 0.1 !! 0.15 !! 0.2 !! 0.25 !! 0.3 !! 0.4 !! 0.5 !! 1 !! 1.25 !! 1.5 !! 1.75 !! 2 !! 2.5 !! 3 
|-
! Fuel per EPH
|0.003||0.009||0.018||0.03||0.05||0.1|| 0.18 || 1 ||1.75||2.76||4.05||5.66||9.88||15.59
|-
! RP cost
|30,000||15,000||8,000||4,000||2,000||1,000|| - || - ||1,000||2,000||4,000||8,000||15,000||30,000
|}

'''Fuel Consumption''':
{| class="wikitable" style="text-align: center;"
! Modifier !! 1 !! 0.9 !! 0.8 !! 0.7 !! 0.6 !! 0.5 !! 0.4 !! 0.3 !! 0.25 !! 0.2 !! 0.16 !! 0.125 !! 0.1
|-
! RP cost
| - ||1,000||2,000||4,000||8,000||15,000||30,000||60,000||120,000||250,000||500,000||1,000,000||2,000,000
|}

'''Thermal Reduction''':
{| class="wikitable" style="text-align: center;"
! Signature (%) !! 100 !! 75 !! 50 !! 35 !! 25 !! 16 !! 12 !! 8 !! 6 !! 4 !! 3 !! 2 !! 1
|-
! Cost Increase
| - ||25%||50%||75%||100%||125%||150%||175%||200%||225%||250%||275%||300%
|-
! RP cost
| - ||1,500||3,000||6,000||12,000||25,000||50,000||100,000||200,000||400,000||750,000||1,500,000||2,500,000
|}

'''Engine Size''' ranges between 1-50 HS. Fuel consumption is reduced by 1% per HS, and HTK is increased per 2 HS. Larger engines are therefore more efficient and [[Internal Damage|sturdy]] at the cost of being less flexible during ship design, less redundant during combat and more expensive to maintain per-unit.

{{Components}}
[[Category:Components]]
[[Category:Designed Systems]]